WirelessHD (WiHD (high definition)) is a standard specified for wireless transmission of an uncompressed baseband video signal and an uncompressed digital audio signal between audio-visual apparatuses.
WiHD is a technical specification for allowing HD video data stored in digital video recorders such as a Blu-ray Disc (registered trademark, hereinafter referred to as BD) recorder, set-top boxes (STB), and personal computers to be displayed on HD televisions without wire connection.
Signals transmitted and received according to WiHD includes bidirectional control signals. A protocol is therefore specified for coordinated operation of a television and a digital video recorder and for central control of apparatuses constituting a home theater system.
In addition, Digital Transmission Content Protection (DTCP) is specified as a content protection method against fraudulent reproduction and illegal copy of content because WiHD allows transmission of high quality content.
The communication model of WiHD includes three functional divisions: the physical layer, the medium access control (MAC) sublayer, and the adaptation sublayer.
Among these divisions, the physical layer has two types of physical data transmission methods specified. Specifically, the two specified physical layers are the high rate physical layer (HRP) and the low rate physical layer (LRP).
The HRP is capable of high-speed transmission in excess of 3 Gbps and used mainly for transmission of uncompressed high quality content. The HRP is highly directional due to characteristics of the frequency band thereof. On the other hand, the LRP uses an omni-directional wave and is used mainly for transmission of control signals and wave path information between apparatuses.
Methods of wireless transmission according to WiHD having such characteristics are disclosed in literatures such as PTL 1 and NPL 1.